Minister Hartcher says finding a replacement for fossil fuels won't be easy, but the state's future depends on it.

"You cannot have business investment, you cannot have economic development without energy supply," he told the gathering.

"If energy prices are not competitive then business investment is going to go elsewhere, either in NSW or in other states, or even go overseas," he said.

The forum was hosted by Regional Development Australia Northern Inland under the auspices of the NSW government.

The Minister defended his government's support of the the CSG meeting, while leaving alternative energy producers off the guest list.

Chris Hartcher says there was nothing untoward about it.

"Where you have new technologies and where you're bringing about rapid change it is the role of government to make sure that the communities are properly engaged and I do think that's a fair request of government," he said.

"Certainly, the companies are the ones that have to explain what they're doing, but the government has to assure the communities that what is being done is going to be done in accordance with the law and that the community's voice is going to be heard."

The meeting heard that NSW has 250 years supply of gas under the ground and Chris Hartcher told delegates his government intends to exploit the resource.

"If we are going to develop the gas, which is what this government intends to do, subject to protecting our farmlands, our water and our environment, then we must ensure the energy that it produces isn't simply a commodity for export," the Minister said.

"If there are opportunities for gas development in the domestic market, we are obliged to look at them, too."

Meanwhile, about 40 protestors turned up to voice their concerns outside the exclusive hotel.

Executive director of an alternative energy company on the Tablelands, Adam Blakester, says his company is working on a number of community-owned projects involving wind and solar energy.

Adam Blakester says the CSG forum is out of touch with simple, economic reality.

"There are a number of problems with coal seam gas; one that it's too costly and the other that it has too little public support," he said.

"APPEA and Santos simply need to put a set of financial numbers on the table for any of us who can interpret them as to how they're going to do this that is in any way affordable, because it's not."

Energy and Resources Minister, Chris Hartcher, did concede that major gas contracts in NSW will begin to expire from 2014.